Rtl logic

Rtl logic. Aim: Develop a Half Adder using Verilog module. 6 V), a current flows from the base to the emitter. Cổng logic có thể được làm bằng hiệu ứng quantum mechanical (cho dù quantum computing thường phân hóa với thiết kế boolean). RTL and DTL families have become obsolete because of their low speed, high power dissipation, and low fan-out. Although RTL-Resistor Transistor Logic is not used much now, but studying its principles is beneficial in understanding the working of other gates. cc" in cosim-demo is just the top of a system in PL, right? We would like to show you a description here but the site won’t allow us. Tessent RTL Pro handles complex Verilog and SystemVerilog constructs and maintains the look and feel of the original RTL design. In this type of AND logic circuit, the transistors are operated in saturated “ON” & “OFF” states. At simulation start, all signals have x’s in every bit. 6 or 0. This article discusses an overview of a Transistor-Transistor Logic or TTL. 翻译. The term “Register Transfer” can perform micro-operations and transfer the result of Apr 26, 2024 · Register transfer level (RTL) is an abstraction for defining the digital portions of a design. Two-input RTL NOR Gate. Expect inquiries about sequential and combinational logic, finite state machines, clock domain crossing, and timing closure. A logic low voltage for ECL is about -1. 0:12 - Definition of Logic Familie This paper proposes a new optimization method for redundant arithmetic logic units in register transfer level (RTL) logic synthesis which can be combined with the existing merging technology to form a more systematic optimization method. tutorialspoint. Tips to solve Logic families questions for GATE ECE Dec 6, 2021 · The main advantage of ECL over approaches like RTL and DTL as well as TTL is that ECL is very fast due to its Notable with IC logic chips produced for the Soviet market is that they use metric The Synopsys next-generation RTL design and synthesis solutions, including Synopsys RTL Architect ™ and Synopsys Design Compiler® NXT , are helping engineers achieve optimal PPA at all process nodes, but especially for 5nm and below. In digital circuit design, register-transfer level ( RTL) is a design abstraction which models a synchronous digital circuit in terms of the flow of digital signals ( data) between hardware registers, and the logical operations performed on those signals. This article reviews the evolution of logic synthesis until the advent of techniques for automatic pipelining based on elastic timing, either synchronous or asynchronous. frequency supply volt. Logic NOT gates provide the complement of their input signal and are so called because when their input signal is “HIGH” their output state will NOT be “HIGH”. Asynchronous operations 5. At high frequencies (>> MHz) CMOS dissipates more power than TTL. Families are identified by the manner in which the elements are connected, and, in some cases, by the types of elements used. Apr 3, 2020 · For one, '1' will be at least 2V below VCC because each transistor is used as an emitter follower, with Vbe=0. Logic gates that use RTL technology are designed using NPN transistors as switches and resistors as current limiters or to implement voltage drops. AND-OR-INVERT Gates MCQs. 1 (2009) in the foreground and you should get the rc startup window: Automate the analysis and insertion of test points, wrapper cells and x-bounding logic earlier in the design flow, at the RTL level. This glue logic does not follow the RTL coding pattern/style. There are a large number of functions in SSI and MSI available Feb 24, 2020 · You might also encounter the terms Register Transfer Logic or Register Transfer Language, they all mean the same in the context of hardware designing. Jan 3, 2023 · RTL でプログラミングすることは、今まで LSI に実装されていなければ諦めるしかなかった低レイヤーの動作にまでプログラマが手を出せる可能性を秘めています。. Behavioral has the highest layer of abstraction which describes the overall behavior and is Aug 25, 2023 · RTL/Logic Synthesis Flow. May 25, 2023 · RTL design is a digital design methodology that focuses on the transfer of data between registers within a digital system. RTL modeling allows Feb 29, 2024 · Understanding RTL Circuits. Logical OR gate can have 2 or more than 2 input lines but it has one output line. Feb 8, 2021 · You should learn about the most widely used logic families such as DL, DTL, RTL, TTL, ECL, MOS, CMOS, etc. eff. RTL design is closer to the system's functionality and is easier to understand and modify, while gate-level design is closer to the physical implementation and provides more accurate High-threshold logic. When both inputs “A” and “B Explanation: RTL NOR gate behaves as NOR gate and the output of NOR gate will be 1 only when all the inputs are at logic 0 and in rest conditions of the input, the output is 0. Inverters, NOR and NAND logic functions can be Jan 12, 2024 · RTL design focuses on the data paths and control logic of the system, while gate-level design focuses on the implementation of the system using logic gates. Common examples of this process include Apr 1, 2024 · Resistor Transistor Logic (RTL) Being the pioneering logic family adopted in integrated circuits, RTL (Resistor-Transistor Logic) circuits consist of resistors and transistors, with resistors positioned at the inputs and transistors at the output. This calls for faster and more effective RTL 5971 Kingstowne Village Pkwy, Suite 200. Out of these, RTL and DTL are rarely used. Demonstrating proficiency in translating 综合流程. – Ignacio Vazquez-Abrams. (LtSPICE simulation, Theory, and Experiment) The BJT circuit shown in Figure 1(a) is an “inverter" or a “logic NOT gate”. ECL-Emitter Coupled Logic MCQs. DTL-Diode Transistor Logic MCQs. RTL Simulation . I simply use two individual bjt's and connect their base and collector together to create a equivalent transistor. One basic thing about the transistor (NPN), is that HIGH at input causes output to be LOW (i. Likewise, when their input signal is “LOW” their output state will NOT be “LOW”. Integers – don’t use these outside of test benches. 2. TTL Logic Families MCQs. Review your resume and cover This logic-generated clock can be dedicatedly taken care during clock synthesis and physical design in ASIC. cadence2009. Its name signifies that transistors perform both the logic function (the first "transistor") and the amplifying function (the second "transistor"), as opposed to earlier resistor–transistor logic (RTL) and diode–transistor logic (DTL). In a computer system, data transfer takes place between processor registers and memory and between processor registers and input-output systems. Our solutions and Ecosystem Partners drive modern real-time embedded applications to ensure the smooth deployment and safe operation of next generation products. Phone: (703) 254-2000. It outputs a bit opposite of the bit that is put into it. capacitance. The paper reviews the Feb 21, 2023 · This course is designed to help you understand core concepts of RTL verification, and become proficient in the latest verification technologies. It has two inputs, A and B, and two outputs, SUM and CARRY. Real Time Logic is an IoT security and web-enablement specialist helping customers develop world class products. The logic NOR gates commercially available have up to four NAND logic inputs. 4-valued logic: 0, 1, x, z. It is the principle abstraction used for defining electronic systems today and often serves as the golden model in the design and verification flow. The bits are typically implemented as two differing voltage levels. Or, if integrating RTL takes effort, although I'm not familiar with systemc modeling, I guess "zynq_demo. 0, 1 – normal binary 0 and 1. In this video, i have explained Resistor Transistor Logic RTL with following timecodes: 0:00 - Digital Electronics Lecture Series. Feb 24, 2012 · Types of Logic Family. Alexandria, VA 22315. The NOR gate is termed a Universal Gate because of its capability to form any other logic using only NOR gates. When the input is high, the output is low, and vice versa. Jan 26, 2023 · Tips to prepare for an RTL design engineer interview Here are some tips to help you prepare for your RTL design interview: Know your terminology. Thanks to the rising demand for high-power, low-cost electronic devices, Integrated Circuits (ICs) and their design have continued to evolve year by year. It is a kind of intermediate representation (IR) that is very close to assembly language, such as that which is used in a compiler. MOS-Metal Oxide Semiconductor MCQs. Feb 29, 2024 · Understanding RTL Circuits. In this article we will discuss how to implement a Half adder Using Verilog HDL. Computer Account Setup Please revisit Simulation Tutorial before doing this new tutorial. – Kevin Sirois. But on FPGAs, it would be big-time fail as we don’t have that flexibility with logic-generated clocks. It is an important characteristic of the digital logic family. The circuit has each input combined through a coupling resistor ( R1, R2, or R3) and fed to the base of Q1. Dec 21, 2018 · The main differences between RTL Design and Sequential Logic Design are summarized below: In RTL Design the basic building blocks are registers, Multiplexers, Adders. The basic building block of this logic family is NAND gate and there are various subfamilies of this logic gate those are standard TTL, advanced Schottky TTL, schottky TTL, low power TTL, high power TTL, fast TTL etc. Register-transfer-level abstraction is used in hardware Logic synthesis. The characteristics of Diode Transistor Logic mainly include; digital cultureless, digital strategist Jul 20, 2022 · Logic Synthesis in Digital Electronics. 6. If the propagation delay is less, then the speed at which the IC operates will be faster. 1. edu WEBThe book contains over 50 digital interview questions, 41 figures and drawings, and 28 practical Verilog code examples, and is a perfect tool to help you succeed on your interview. Register transfer level is a level of description of a digital design in which the clocked behavior of the design is expressly described in terms of data transfers between storage elements in sequential logic, which may be implied, and combinatorial logic, which may represent any computing or arithmetic-logic-unit logic. Keeping in view the importance of miniaturization today, the book gives practical information on the issues with ASIC RTL design and how to overcome these concerns. Register-transfer level. The book constructs the logic design story from the fundamentals of logic design to advanced RTL design concepts. Digital ICs are designed using either bipolar devices, MOS devices, or a combination of both. At its core, RTL employs resistors and bipolar junction transistors (BJTs) to perform logic functions. Otherwise, provide high state “1” as output. In Sequential Logic Design the basic building blocks are the Logic Gates, Flip-Flops. It is called so because the logic gating functions AND and OR are performed by diode logic, while logical inversion (NOT) and amplification (providing signal restoration) is performed by a transistor (in contrast with RTL Logic Rtl Verilog Interview Questions - stage. As they are single input devices, logic NOT gates are not Sep 5, 2021 · I'm expecting to access my RTL IP from the running Linux in QEMU --- In simulation without hardware. Sapatnekar Abstract—Design automation has been one of the main pro-pellers of the semiconductor industry with logic synthesis being one of the core technologies in this ﬁeld. 1. 75V. The clock signal get routed through LUTs on FPGA fabric, and drives the synchronous blocks with poor skew, latency, jitter and slew Feb 24, 2012 · The full form of TTL is Transistor Transistor Logic. 7V. Mar 21, 2018 at 1:55. Programmed production of logic components in a specific digital RTL Inverter. Oct 12, 2022 · Propagation delay. May 12, 2013 · HDL (Hardware description Language) is the type of language used, Verilog/VHDL versus a non-HDL javascript. Running the Cadence logic synthesis tools Now you should be able to run the Cadence tools. 375 Lecture 5 Guest Lecture by Srini Devadas 2 RTL Design Flow RTL Synthesis HDL netlist logic optimization netlist Library/ module generators physical design layout manual design a b s q 0 1 d clk a b s q 0 1 d clk 3 Two-Level Logic Minimization Can realize an arbitrary logic function in Apr 23, 2024 · Key Interview Topics: RTL Design Fundamentals: RTL design engineer interview questions often begin with assessing candidates' understanding of fundamental digital design concepts. Let T HL is the propagation delay when the output changes from logic 0 to You may need glue-logic between systems to facilitate this coordination and communication. SOUND GOOD? READ ON. A two input RTL circuit is shown below. Mar 21, 2018 at 1:15. Developed in the late 1950s and early 1960s, RTL circuits represented a significant advancement over their predecessors, such as vacuum tube-based circuits, offering improved reliability, efficiency, and scalability. It can be either true or false, true being High state”1” and false being Low state”0”. Gowthami Swarna, Tutorials Point I Resistor-transistor logic (RTL) is constructed from resistors and transistors. gedit env. e. This is a logic family which is mainly build up of NPN transistors, PN junction diodes and diffused resistors. RTL 描述会被综合工具转换为一个未经优化的中间表示。. The figure below shows a simple 3-input RTL circuit which is a NOR gate. The process of resolving into component parts or analyzing, interpreting, translating, optimizing (rearranging or rewriting to improve efficiency), and mapping RTL (Register Transfer Level) code into a particular and indicated cell library. Dec 16, 2018 · The following section discusses the important scenarios during the RTL design and the performance improvement techniques. 1 Parallel Versus Priority Logic. MOS families include PMOS, NMOS, and CMOS. Overall advantage is still for CMOS even for very fast chips – only a relatively small portion of complicated circuitry operates at highest Datatypes. RTL-Resistor Transistor Logic MCQs. CMOS excels in low power consumption and high noise immunity. In digital logic, an inverter or NOT gate is a logic gate which implements logical negation. In computer engineering, logic synthesis is a process by which an abstract specification of desired circuit behavior, typically at register transfer level (RTL), is turned into a design implementation in terms of logic gates, typically by a computer program called a synthesis tool. The output of an ECL system has a very low impedance, thus having a fan-out of about 25. RTL was followed by diode-transistor logic and transistor-transistor logic (see DTL and TTL). A good design that can meet the timing requirements is one part of the flow, and the design’s verification is the second part. It is the fastest amongst all the logic families. Synopsys RTL Architect is a predictive RTL design solution that provides early predictions of the impact RTL The Logic NOT Gate Truth Table. By the end Digital Logic Rtl Verilog Interview Questions (2023) ; … In the following figure, a basic two-input AND gate constructed using Resistor-Transistor Logic (RTL) are shown. IIL-Integrated Injection Logic MCQs. The resistor-transistor logic (RTL) are digital circuits that are constructed using resistors and bipolar junction transistors (BJTs). Synthesis is the process of automatically generating gate-level netlists from RTL descriptions written in hardware description languages (HDLs) such as Verilog or VHDL VLSI CAD Flow: Logic Synthesis, Placement and Routing 6. Cổng Photonic logic Inverter (logic gate) Traditional NOT gate (inverter) symbol. Sep 27, 2023 · As seen from the table, each logic family has its own set of characteristics and trade-offs. 用硬件描述语言（例如 Verilog）设计数字电路，并进行仿真保证逻辑功能的正确性。. When the input is high (3. The RTL design is usually captured using a hardware description language (HDL) such as Verilog or VHDL. The emergence of these techniques can enable a productive interaction The NOR logic gates can be constructed using Resistor-Transistor Logic (RTL) but are seldom used because of the propagation delay and power consumption. 7V to -1. The resistors (R1 and R2) in the circuit are connected at the input side & transistors (Q1 and Q2) are connected at the output side. Question: Design and show the logic table for an RTL logic circuit with three inputs (V1,V2,V3) that will only output a HIGH signal if (V1,V2) are HIGH and V3 Question: (Part 1) Resistor-Transistor Logic (RTL) - "NOT” gate. Figure-1:Logic Symbol of AND Gate Figure-2:Truth Table of AND Gate. Resistor-Transistor Logic (RTL): Resistor-transistor logic gates use Transistors to combine multiple input signals, which also amplify and invert the resulting combined signal. Here the circuit used is a 2-input RTL NOR gate which is designed with resistors and transistors. Schematic of basic unbuffered three-input HTL NAND gate. like a inverter). 从高层次 RTL 描述到门级网表的详细综合过程如下图所示。. Also, don’t forget to study unipolar, bipolar[saturated and non-saturated] logic families; direct questions of identification are common in exams from this topic. RTL Design is much closer to the Behavioural Design of a Logic Circuit as it models the data The different logic families are RTL(Resistor Transistor Logic), DTL(Diode Transistor Logic), TTL(Transistor-Transistor Logic), ECL(Emitter Coupled Logic) & CMOS(Complementary Metal Oxide Semiconductor Logic). Logic Optimization • Perform a variety of transformations and optimizations – Combinational transformations • Technology independent • Technology dependent – Sequential transformations • FSM state assignment • Retiming logic optimization netlist netlist pre-optimized smaller, faster less power Library a b s q 0 1 d clk a b s q 0 1 The control paths that initiates the sequence of micro-operation. One-Transistor RTL Gate. CUDA などの GPGPU 用のプログラミング言語で、並列プログラミングに挑戦したことのある方も A basic RTL inverter and its VTC are shown in the gure on the left and right above, Dec 11, 2019 · Characteristics of ECL Logic Families. TTL offers a good balance between power consumption, speed, and noise immunity. Resistor–transistor logic (RTL) is a class of digital circuits built using _______ as the input network and _______ as switching devices. 该过程读入 Verilog 描述的基本原语 Mar 21, 2018 · Using discrete components. In RTL (resistor transistor logic), all the logic are implemented using resistors and transistors. Bipolar logic families include diode logic (DL), emitter-coupled logic (ECL), resistor-transistor logic (RTL), diode-transistor logic (DTL), and transistor transistor logic (TTL). 3. 0:12 - Resistor Transistor RTL was widely used before the development of ICs. High-threshold logic ( HTL ), also known as low-speed logic ( LSL) or high-level logic ( HLL ), is a variant of diode–transistor logic used in environments where noise is very high. Mar 20, 2020 · The RTL circuits basically performs the NOR operation. A half adder is a digital logic circuit that performs binary addition of two single-bit binary numbers. Kratos has deep experience delivering a large set of integrated products, antennas, and equipment as a system for customers looking to implement large solutions. TTL is the most popular general purpose logic family. TTL power essentially constant (no frequency dependence) CMOS power scales as ∝ f × C × V2. x – simulator doesn’t know; sometimes used as “don’t care”. RTL is a higher level abstraction for your digital hardware design and comes somewhere between strictly behavioral modeling on one end and purely gate-level structural modeling on other ends. Synthesizable and Non-Synthesizable Verilog constructs Synthesizable Non-Synthesizable Basic Identifiers, escaped identifiers, Sized constants (b, o, d, h), Unsized constants (2'b11, 3'07, 32'd123, 8'hff), Signed constants (s) 3'bs101, module, endmodule, macromodule, ANSI-style module, task, and function port Diode–transistor logic ( DTL) is a class of digital circuits that is the direct ancestor of transistor–transistor logic. 2. DCTL-Direct Coupled Transistor Logic MCQs. and combinational logic, RTL design enables efficient and optimized should optimize their RTL designs sufficiently at this stage, since it is extremely challenging, if not impossible, to remedy low-quality RTL in downstream synthesis stages. The RTL design is a low-level A logic gate which gives low state “0” only and only when all of the inputs are low state “0”. Fax: (703) 254-2010. ECL is a logic family based on BJT that achieves high-speed operation by employing a very small voltage swing and avoiding RTL Compiler for logic synthesis. The resistance is connected in the base and both input is applied to the base of both the transistor. This circuit is a member of Resistor-Transistor Logic (RTL) family of logic gates, where we use one or more BJTs and resistors to build the logic gate. Resistor Transistor Logic (RTL)Watch more videos at https://www. One is TTL, the other is not (RTL). 8V. NPN transistors serve as switches, while resistors either regulate current or introduce voltage drops. The three levels I refer to are Behavioural, RTL, Gate-level. htmLecture By: Ms. The propagation time is about 1ns, making it the fastest logic family. FZH251, four two-input HTL AND. RTL 描述. The DTL has many benefits as compared to resistor transistor logic like; the higher fan-out values & high noise margin thus, DTL is replaced RTL family. The disadvantage of Diode logic (DL) is overcome using RTL since the transistors not only operate as switches but also Feb 11, 2022 · Register Transfer Language (RTL) In symbolic notation, it is used to describe the micro-operations transfer among registers. RTL circuits are made of Resistor Transistor and are the first logic families to be integrated. Logic families are groups of logic circuits that are based on particular types of elements (resistors, transistors, and so forth). Both transistors must be saturated “ON” for an output at Q. May 8, 2015 · A wide range of information and topics are covered, including: RTL Verilog coding syntax, RTL Logic Design (including low power RTL design principles), clocking and reset circuits, clock domain crossing questions, digital design fundamentals, and logical thinking questions. Be prepared to talk about logic gates, programming and problem-solving skills like simple circuits. During the RTL design phase, it is important to visualize the synthesis outcome of the RTL. (2) (Register Transfer Level) A high-level hardware description language (HDL) for defining digital What is the proper way to implement clock gating in RTL? The clock gating signal should only toggle when the latch is closed, otherwise there is a chance for glitches and metastability issues. The resistor transistor logic circuit is shown below. The collector end of both the transistor are joined together and About this book. In this logic circuit, diodes are useful in performing logic functions, while transistors are used to perform the amplification functions. Feb 18, 2021 · In this video, i have explained Digital Logic Families with following timecodes: 0:00 - Digital Electronics Lecture Series. In logic circuit diagrams the power is not shown, but in a full electronic schematic, power connections are required. In order to setup your environment to run Cadence applications you need to open an xterm window and type: . Sep 24, 2015 · Design automation has been one of the main propellers of the semiconductor industry with logic synthesis being one of the core technologies in this field. Despite the critical importance of optimizing RTL designs, it is very difficult to evaluate the RTL design quality, considering an RTL design is still in the format of HDL What is Logic Synthesis? §Design described in a Hardware Description Language (HDL) –Verilog, VHDL §Simulation to check for correct functionality –Simulation semantics of language §Synthesis tool –Identifies logic and state elements –Technology-independent optimizations (state assignment, logic minimization) Cổng logic được xây dựng dựa trên DNA (xem DNA nanotechnology) [9] và được sử dụng để xây dựng một máy tính tên là MAYA (xem MAYA II ). This book is designed to serve as a hands-on professional reference with additional utility as a textbook for upper undergraduate and some graduate courses in digital logic design. nwcc. Gated clocking 4. The transistor works as switch. now to know Jul 16, 2023 · Half Adder Using Verilog. Click on the input on the left to toggle its state. The command rc -gui (no &) starts RTL Compiler version 8. We would like to show you a description here but the site won’t allow us. z – high-impedance value: this is what tri-state buffers drive when they are off. And with only a 5K pulldown it won't interoperate well with traditional TTL whic requires sinking a certain current from a TTL input to maintain a clean logic '0'. For each input, a Transistor (T) is used and the output is driven across the Resistor (R). Pipelined design employing data-stationary control (you do not describe this using a “ case (state)” construct). Nov 3, 2021 · Figure 4: Synchronous RTL Logic . It is available in seven different series with a wide range of operating speed, power dissipation and fan-out. tcl Change the simulation mode from “rtl” to “syn”. Resulting RTL output simplifies the flow of downstream tools allowing synthesis to Jul 1, 2016 · In this video, I have described the operation of RTL NOR Gate . RTL synthesis: from logic synthesis to automatic pipelining Jordi Cortadella, Marc Galceran-Oms, Mike Kishinevsky, and Sachin S. It is the time interval between the application of the input pulse and the occurrence of the output. This paper presents an optimization method for redundant arithmetic logic units in register transfer level (RTL) logic synthesis. Apr 14, 2023 · RTL (Register Transfer Level) design is the process of creating a digital logic design using a hardware description language (HDL), such as Verilog or VHDL. So transistors will typically have a voltage drop across them Transistor–transistor logic ( TTL) is a logic family built from bipolar junction transistors. Direct-coupled transistor logic ( DCTL) is similar to resistor–transistor logic (RTL) but the input transistor bases are connected directly to the collector outputs without any base resistors. The Resistor Transistor Logic (RTL) is considered to be the first logic family that was introduced for integrated circuits. CMOS-Complementary Metal Oxide Semiconductor MCQs. This book is organized in such a way that that it can describe a number of RTL design scenarios, from simple to complex. com/videotutorials/index. ECL provides exceptional speed but at the cost of high power consumption. Transistors either connected in series or parallel. The book contains over 50 digital interview questions, 41 figures and Most digital logic gates and digital logic systems use “Positive logic”, in which a logic level “0” or “LOW” is represented by a zero voltage, 0v or ground and a logic level “1” or “HIGH” is represented by a higher voltage such as +5 volts, with the switching from one voltage level to the other, from either a logic level “0” to a “1” or a “1” to a “0” being Oct 25, 2022 · Emitter-coupled logic is a logic and interfaces technology that is utilized in highly fast communications devices such as fiber-optic transceiver interfaces, Ethernet, and ATM (Asynchronous Transfer Mode) networks. RTL (Register-transfer level) is a level of abstraction that you are writing in. The resistors are the input network while the transistors function as switching devices. Even if you know the material well, brush up on vocabulary and terms. There are RTL design simulators like Modelsim used for the verification of the design through simulation and debugging. An important existing In this screencast, we explore the RTL Viewer in Quartus Oct 3, 2023 · IC Logic Families MCQs. Logic circuits of a particular family can be interconnected without having to use Congratulations, this is the end of the Logic Synthesis Tutorial Assignment: Post-synthesis simulation Now that you are done with the synthesis, it’s time to simulate the accumulator using the design as implemented using cells from the 45 nm standard cell library. RTL CODING FOR LOGIC SYNTHESIS 1. A simple 2-input logic AND gate can be constructed using RTL (Resistor-Transistor-Logic) switches connected together as shown below with the inputs connected directly to the transistor bases. The Register Transfer Language is the symbolic representation of notations used to specify the sequence of micro-operations. For an active high latch, the gating signal should toggle on the falling edge of the clock. This is an inverter implemented using resistor-transistor logic, the earliest form of logic implemented with transistors. A logic high voltage for ECL is about -0. ax hf mu vl ez kb jm zo kr sa